POSSIBLE Effects of Changing Climate Patterns on Reptile and Amphibian Populations in SC Steve Bennett SCDNR-Wildlife and Freshwater Fisheries, Herpetologist Retired I’LL FOCUS ON THE COASTAL PLAIN BECAUSE THAT’S WHAT I AM MOST FAMILIAR WITH AMPHIBIANS ARE FIRST RESPONDERS Salamander Populations and Biomass in the Hubbard Brook Experimental Forest, New Hampshire Thomas M. Burton and Gene M. Likens There were about 2,950 salamanders per ha (1,770 g/ha wet wt.) in the Hubbard Brook Experimental Forest in New Hampshire. The terrestrial species, Plethodon cinereus, accounted for about 93.5% of the total biomass while the streamside species, Desmognathus fuscus, Eurycea bislineata and Gyrinophilus porphyriticus, accounted for the remaining 6.5%. Notophthalmus viridescens was present, but was rare and insignificant in the biomass calculations. The population size of salamanders at Hubbard Brook appears to be stable. The biomass of salamanders is about twice that of birds during the bird's peak (breeding) season and is about equal to the biomass of small mammals 4 POUNDS OF SALAMANDER BIOMASS PER ACRE HUBBARD BROOK = 7660 ACRES 30640 POUNDS OF SALAMANDERS 15 TONS OR 13.9 METRIC TONS 2003 EBAY Amphibian Biomass 1400 1305 1200 1000 EBAY = 24 acres 800 Drift fence = .8 mi. 82 buckets per side 600 3.1 Tons 400 226 200 46 25 1.4 0.24 0.22 0.01 0 P. ornata B. terrestris A. tigrinum H. gratiosa A. opacum H. squirella A. talpoideum R. sphenocephala Potential Impacts of Climate Change on Ecosystems Changes in the Timing of Seasonal Life- Cycle Events Range Shifts Food Web Disruptions Threshold Effects Pathogens, Parasites, and Disease Extinction Risks Source: EPA Potential Impacts of Climate Change on Ecosystems Models do suggest that rainfall will arrive in heavier downpours with increased dry periods between storms. Sea level rise along the Southeast coast will likely erode wetlands and coastal shorelines. Low-lying areas would be flooded more frequently. Higher temperatures increase evaporation and water loss from plants. Projected increases in temperature will likely increase the frequency, duration, and intensity of droughts in the area. [3] If the region increases groundwater pumping to offset water shortfalls, then aquifers will be further depleted. In the long term, the depletion of ground water supplies would place additional strain on surface water resources. [3] EXAMPLE 1 – TEMPORARY, ISOLATED WETLANDS CAROLINA BAYS, VERNAL POOLS, FLATWOODS PONDS, SWALE PONDS, HIGH PONDS ETC. TYPICAL CHARACTERISTICS PERCHED WATER TABLES NOT CONNECTED TO SURFACE STREAMS PULSED HYDROLOGY DRIVEN BY RAINFALL CYCLES DETRITUS BASED FOOD WEBS PREDATORY FISH ARE TYPICALLY ABSENT VARIABLE CHARACERISTICS A VARIETY OF PLANT COMMUNITIES POSSIBLE BASIN SIZE AND DEPTH PERCHING MECHANISM LOCATION IN LANDSCAPE Typical Year … but there are no typical years PONDS MAY HOLD WATER FOR MULTIPLE YEARS OR BE DRY FOR MULTIPLE YEARS DEPENDING UPON RAINFALL PATTERNS AMPHIBIANS AND “PONDS” IN THE COASTAL PLAIN OF SOUTH CAROLINA 49 SPECIES OF AMPHIBIANS OCCUR IN SC COASTAL PLAIN 33 OF THESE SPECIES (69%) USE PONDS FOR BREEDING HABITAT (SOME LIVE IN THE PONDS YEAR ROUND) 11 OF THESE SPECIES ARE ENDEMIC TO, OR STRONGLY SELECTIVE OF PONDS AS BREEDING SITES 3 OF THESE SPECIES ARE PROTECTED UNDER STATE OR FEDERAL LAW FLATWOODS SALAMANDER-FEDERALLY THREATENED GOPHER FROG-STATE ENDANGERED DWARF SIREN-STATE THREATENED BARKING TREEFROG OAK TOAD CAROLINA GOPHER FROG SPADEFOOT TOAD ORNATE CHORUS FROG MABEE’S SALAMANDER (LARVA) DWARF SIREN FLATWOODS SALAMANDER MOLE SALAMANDER DIRK STEVENSON MARBLED SALAMANDER SPOTTED TURTLE GLOSSY CRAYFISH SNAKE CHICKEN TURTLE BANDED WATERSNAKE MUD SNAKE EASTERN MUD TURTLE BLACK SWAMP SNAKE “POND” HYDROLOGY IS COMPLICATED! BUT RAINFALL IS KEY AVERAGE DATE OF FILLING HYDROPERIOD (LENGTH OF TIME POND HOLDS WATER) EXTREMES EL NINO … EXCESSIVE RAIN FILLS PONDS HEY EXPERIENCE AN EXTENDED HYDROPERIOD, SOMETIMES 2-3 YEARS OR MORE THIS IS NOT NECESSARILY “GOOD” LA NINA … DROUGHT CONDITIONS AND PONDS DON’T FILL FOR MULTIPLE YEARS THIS IS DEFINITELY NOT “GOOD” Scott et al, SREL/SRS have documented a 7 day decrease in average Hydroperiod and an 8 day (later) change in average date of filling Since 1978, for Rainbow Bay, a Carolina bay at SRS that has been studied for 25+ years 4 YEARS ? 1999 ESTIMATED LIFE SPANS FOR SELECTED AMPHIBIANS: TIGER SALAMANDER – 15-20 YEARS DWARF SIREN - 20+ YEARS SPOTTED SALAMANDER – 20-30 YEARS BULLFROG - 10-16 YEARS GOPHER FROG – 6-7 YEARS? FLATWOODS SALAMANDER – 4 YEARS? A SIMPLE POPULATION MODEL: A BREEDING PAIR OF FROGS OR SALAMANDERS MUST REPLACE THEMSELVES ONCE IN A LIFETIME, ABSENT ANY MORTALITY IN THE POPULATION TO MAINTAIN A STABLE POPULATION … ANYTHING MORE RESULTS IN AN INCREASING POPULATION, ANYTHING LESS A DECLINING POPULATION. HYPOTHESIS: THE LIFE SPAN, AND POSSIBLY AGE TO FIRST REPRODUCTION FOR POND BREEDING AMPHIBIANS IS DETERMINED BY THE AVERAGE FREQUENCY OF INUNDATION OF THEIR BREEDING PONDS. IN OTHER WORDS … IF YOUR BREEDING POND(S) ONLY FILL ONCE EVERY 3-4 YEARS YOU BETTER LIVE AT LEAST 3-4 YEARS AND LONGER IS BETTER TO ACCOMMODATE VARIABILITY. WHAT HAPPENS IF THE AVERAGE TIME BETWEEN INUNDATION INCREASES, ALONG WITH THE ALREADY DOCUMENTED REDUCTION IN HYDROPERIOD AND LATER DATE OF FILLING? Potential Impacts of Climate Change on Ecosystems Changes in the Timing of Seasonal Life- Cycle Events Range Shifts Food Web Disruptions Threshold Effects Pathogens, Parasites, and Disease Extinction Risks Source: EPA EXAMPLE 2 – SEEPAGE WETLANDS SEEPS, BOGS, FENS SPRINGS, HEADWATERS ETC. SEEPAGE WETLAND CHARACTERISTICS . TYPICALLY AT THE OUTER EDGE OF A STREAM CORRIDOR . OCCUR AT OR NEAR THE BASE OF SLOPES AND BLUFFS . PRIMARY WATER SOURCE IS EMERGING SUBSURFACE WATER . PREDATORY FISH TYPICALLY ABSENT . SALAMANDERS OF THE FAMILY PLETHODONTIDAE ARE THE . DOMINANT VERTEBRATES . VARIABLE IN SIZE … WIDTH AND LENGTH OF STREAM AND WATER FLOW TWO-LINED SALAMANDER THREE-LINED SALAMANDER RED SALAMANDER MANY-LINED SALAMANDER “DUSKY” SALAMANDER MUD SALAMANDER FAMILY PLETHODONTIDAE CHAMBERLAIN’S DWARF SALAMANDER “LUNGLESS SALAMANDERS” PINE BARRENS TREEFROG FIRE IS THE KEY If the region increases groundwater pumping to offset water shortfalls, then aquifers will be further depleted. In the long term, the depletion of ground water supplies would place additional strain on surface water resources. [3] RESULTS – SEEPS DRY UP AND CANNOT SUPPORT SALAMANDERS DRY CONDITIONS MAKE PRESCRIBED FIRE DIFFICULT AFFECTING AVAILABILITY OF BREEDING HABITAT FOR THE PINE BARRENS TREEFROG Food Web Disruptions Threshold Effects Extinction Risks AMPHIBIANS ARE FIRST RESPONDERS …”CANARIES IN THE COAL MINE” WHEN IT COMES TO ANYTHING THAT CHANGES MOISTURE REGIMES, HYDROPERIODS OF TEMPORARY PONDS AND SEEPS AMPHIBIANS COMPRISE A LARGE PERCENT OF THE STANDING BIOMASS IN MANY SYSTEMS … THEY PLAY AN IMPORTANT ROLE IN FOOD WEBS A NUMBER OF RARE AMPHIBIAN AND REPTILE SPECIES ARE DEPENDENT UPON TEMPORARY PONDS … LOSS OF THIS HABITAT COULD LEAD TO EXTINCTIONS CHANGES IN THE HYDROLOGIC CYCLES OF TEMPORARY PONDS AND SEEPS COULD BE DETRIMENTAL TO APPROXIMATELY 80% OF THE AMPHIBIAN SPECIES FOUND IN THE S.C. COASTAL PLAIN! .